The invention relates to an electromechanical knocking device and knocking method for smoothing and cold-hardening the surface of tools, machine parts and other parts by hammering on the surface of said parts for mounting them on a machine tool or a robot. A device of this kind is shown by laid-open patent application no. DE 197 32 790.7-14. In said device, a slide is moved axially with a constant amplitude by the rotation of a disc, which is embodied with undulations in the circumferential direction, on a non-rotating second disc which is embodied with undulations in the opposite direction. A spherical head which impacts on the workpiece surface is located at the workpiece end of the slide.
In practice, this device has substantial disadvantages. The impact movements are produced in a mechanically interlocking manner. As a result, the device is subjected to the enormous abrasion of the cam disc or undulating disc. The head strikes the workpiece surface with a constant amplitude, irrespective of the position, shape and stiffness or hardness of the surface. This limits the use of said device to a few cases.
The laid-open patent application no. DE 102 43 415 A1 describes a similar device in which the head is moved by converting ultrasound into a mechanical movement. However, this laid-open patent application does not disclose the manner in which the ultrasound is converted into movement of the impacting head, and does not refer with a single word to the amplitude of the impact.